Furby in coma.

[Marie-Anne Nogues]

Hello resourceful souls,
For the context, I was 50 this year. This Furby landed in the garden we had in the shared house in 1999 while I was a mature student at Uni. I know each to their own. I am pretty childish...
I just found it again in my stuff/clutter and I thought it would be a great 50th birthday present to myself if I could bring it back to life.
I checked the corrosion and scrubbed it off.
add a set of fresh batteries. nothing
moved gently, ears, eyes and mouth. nothing.
Pressed the reset button and reset and tongue button: nothing.
I skinned it and tried to jump start it up with moving the motor wheel and the coil on the right side: still in coma.
My son, 19, still thinks I can fix anything. So far Furby defeated me. Can you help?
Overall it looks in a good shape: connection of wiring and no corrosion appearing.
It feels like all the mechanisms are loose but the power does not reach them.
It just feels out of my league. Electronics are not my favourite playground.
Any insight is much appreciated.
Marie-Anne